目录
一.题目
1.Birdman's Data
2.Look At Me
3.Otter Leak
一.题目
网址
OtterCTF
1.Birdman's Data
下载文件:
.pcap文件 Wireshark打开:
既然是web 我们就从http分析:
追踪流 HTTP流:
发现两个密钥key:
{"key":"XfCtxvD1yFZbxQ/+ULhAcA=="}
{"key":"sEhrZxQpnNnINixu3KQ1Tg=="}
继续找:
发现cipherText(密文)
密文:
{"cipherText":"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"}
受害者使用了这样的:Key和IV
在线工具解密:
Encryption, Hashing, and Encoding Tools - AES, MD5, SHA256, Base64 | TxtWizard
假设第一个密钥参数是 Key,第二个是 IV
复制过来:
发现开头 一列就是flag:
Chance Something's wrong, I can feel it (Six minutes, Slim Shady, you're on) Just a feeling I've got, like something's about
To happen, but I don't know what If that means, what I think it means, we're in trouble, big trouble, And if he is as bananas as you say, I'm not taking any chances You were just what the doctor ordered I'm beginning to
Feel like a Rap God, Rap God All my people from the front to the back nod, back nod Now who thinks their arms are long
{
Enough to slap box, slap box? They said I rap like a robot, so call
me Rapbot But for me to rap like a computer must be
in my genes I got a laptop in my back pocket My pen'll go off when I half-c*** it Got a fat knot from that rap profit Made a living and a killing off it Ever since Bill Clinton was still in office With Monica Lewinsky feeling on his
Nut-sack I'm an MC still as honest But as rude and indecent as all hell syllables, killaholic (Kill 'em all with) This slickety, gibbedy, hibbedy hip hop You don't really wanna get into a pissing match with this rappidy rap Packing a Mac in the back of the Ac, pack backpack rap, yep, yackidy-yac The
exact same time I attempt these lyrical acrobat stunts while I'm practicing That I'll still be able to break a
Motherf***in' table Over the back of a couple of
_
Faggots and crack it in half
Only
Realized it was ironic I was signed to Aftermath after the fact How could I not blow? All I do is drop F-bombs, feel my wrath of attack Rappers are having a rough time period, here's a Maxipad It's actually disastrously bad For the wack while I'm masterfully constructing this masterpiece as I'm beginning to feel
_
Like a Rap God, Rap God All my people from the front to the back nod, back nod Now who thinks their arms are long enough to slap box, slap box? Let me show you maintaining this s*** ain't that hard, that hard Everybody want the key and the secret to rap
immortality like I have got Well, to be truthful the blueprint's simply rage and youthful exuberance Everybody loves to root
for a nuisance Hit the
Earth like an asteroid, did nothing but shoot for the moon since MC's
_
get taken to school with this music Cause I use it as a vehicle to bust a rhyme Now I lead a new school full of students Me? I'm a product of Rakim, Lakim Shabazz, 2Pac N- -W.A, Cube, hey, Doc, Ren, Yella,
Eazy, thank you, they got Slim Inspired
enough to one day grow up, blow up and be in a position To meet Run DMC and induct them into the motherf***in' Rock n' Roll Hall of Fame Even though I walk in the church and burst in a ball of flames Only Hall of Fame I be inducted in is the alcohol of fame On the wall of shame You fags think it's all a game 'til I walk a flock of flames Off of planking, tell me what in the f*** are you thinking? Little gay looking boy So gay I can barely say it with a straight face looking boy You witnessing a massacre Like you watching a church gathering take place looking boy Oy vey, that boy's gay, that's all they say looking boy You get a thumbs up, pat on the back And a way to go from your label everyday looking boy Hey, looking boy, what you say looking boy? I got a "hell yeah" from Dre looking boy I'mma work for everything I have Never ask nobody for s***, get outta my face looking boy Basically boy you're never gonna be capable To keep up with the same pace looking boy 'Cause I'm beginning to feel like a Rap God, Rap God All my people from the front to the back nod, back nod The way I'm racing around the track, call me Nascar, Nascar Dale Earnhardt of the trailer park, the White Trash God Kneel before General
zorb
}
也可以kali命令:
cat plaintext.txt | cut -c 1 | tr -d '\n'
CTF{EmiNeM_FOR_LifE_gEez}
2.Look At Me
下载.pcap
先查为敬:
MD5:d7dbb2394596594b438ab3110ace3408
SHA1: fc16f0636a7f141b8b17e0e7a38b776dd5c21c82
SHA256: 22a52be210bde91e1c2afb3e4643e3f437b6c3e3bcdc1e3f538694d4305af1f6
鲨鱼打开:
发现看不懂。。。
网上找大佬:
这似乎是来自Wacom CTL-471绘图板的USB数据,
Wacom CTL-460 平板电脑的 USB 流量,这对解决这一挑战有很大帮助。
我们需要的剩余捕获数据的数据包可以根据帧长度在 Wireshark 中进行过滤......
BITSCTF – Tom and Jerry (50分) – tunelko。
过滤一下:
((usb.transfer_type == 0x01) && (frame.len == 37))
然后用tshark提取到单独的PCAP中进行进一步处理。
tshark -r look_at_me.pcap -w filtered.pcap -Y '((usb.transfer_type == 0x01) && (frame.len == 37))'
此数据包含在 usb.capdata 字段中;我们可以再次使用 tshark 将其提取到文本文件中并丢弃 PCAP 的其余部分。
tshark -r filtered.pcap -T fields -e usb.capdata -Y usb.capdata > usb.capdata.txt
用python脚本把原始十六进制值转换为小端 X/Y 和 Z 坐标:
python ./flag.py
look一下:
安装gnuplot包
gnuplot
flag2.py:
#!/usr/bin/python
from pwn import *
for line in open('usb.capdata.txt.xyz').readlines():
coord = line.strip().split(' ')
x = int(coord[0],16)
y = int(coord[1],16)
z = int(coord[2],16)
if z > 0:
print (u16(struct.pack(">H",x)),u16(struct.pack(">H",y)))
进入gnuplot
plot "flag.txt"
保存为flag.png
用命令翻转它以便于查看
再次查看:
CTF{0TR_U58}
3.Otter Leak
鲨鱼打开
统计---协议分析
看到各协议占的百分比:
我们可以看到一些SSH流量,但目前更有趣的是通常用于传输文件的SMBv2流量。
导出对象---SMB:
检查“导出 SMB 对象”窗口,我们可以看到大量文件的名称表明它们是图像,但文件大小仅为 1 字节。让我们将它们全部导出到一个新目录,看看我们有什么。
cat export/%5cotter-under-water.jpg.638x0_q80_crop-smart*
LS0gLS0tLS0gLi0uIC4uLi4uIC4gLS0tIC0gLS0uLi4gLi4uLS0gLi0uIC4uIC0uIC0uLi4gLS4uLi4gLi4uLi0=
我们的输出具有 = 填充,表明我们可能正在处理 base64 编码。
CyberChef
运行 From Base64 操作会给我们flag
CTF{M0R5EOT73RINB64}
附:
别问为什么没有第四题 问就是不会。。。。。太难了.....
参考文章:
OtterCTF 2018 – Network Challenges – Look At Me Write-up – peter m stewart dot net